Means for reproducing position



Julyl28, 1925. 1,547,392

E. Mv. HEWLETT ET AL MEANS Fon REPRODUGING PosITIoN Filed Aug. 2. 192s f 2 Y i l n Patented .my 28,192'5 1 UNITED 'STATES lrarau'r OFFICE.

M. HEWLETT .ANDWALDO W. WILLARD, F SCHE-YECTADY, NEW YORK, .AS- SIGNOBS T0 GENERAL ELECTRIC COMPANY', A. $0ItaliOIRtAlION'- 0F NEW YORK.

. S Application led August 2,- 1923. Serial No. 655,359.

To all whom it' may concern:

e it known that' we, EDWARD M. Huw- Ln'rr'and WALDO W. WILLARD, citizens of the United States, jresidin at Schenectady,

5 county of Schenectady, tate of New York,

have invented certain new and useful lmprovements in Means for Reproducing Position', of which the following is a specification.

This invention relates to means for reproducing position, and has for its object the provision of means comprising power amplifying devices for controlling a remote driving motor.

More specifically our invention relatos to systems for reproducing position in which the motion of a controlling object is utilized through suitable mechanism to control a remote servo motor so as to cause the servo motor to drive a second or controlled object 29 into positional agreement with the irs't.

in carrying out our invention vve controi V'the remote servo motor hy means ci electron discharge devices and control the electron discharge devices in turn by means of an electrornotive force which is substantially proportional in amount and direction to the positional disagreement between the two objects. Y

For a better understan-ding of our invention reference should be had to vthe accom=l panying drawing, Fig. 1' of which shows in diagrammatic form .means for reproducing position embodying our invention, while Figs. f2 and 3 are modied forms of our invention. i

Referring to the drawing, We have shown our invention in one forni 'as applied to they automatic controlling ci the position of a remote searchlight 10 so as to' maintain 'the searchlight'ina predetermined angular relation with a controlling object which is shown as a telescope 11. It is desired, for example, to automatically move the searchlight so that it is directed on the object at which the telescope is connected to the telescope 11 is an inductive device ,12 comprising in the form shown a field winding 13 lrotatably mounted andy in a s/tadrivenby movement of the telesco horizontal Plane or in azimuth, an a tionary po y'c'ircuit armature windin 14 shown as a three-'phase distributed winding. The field winding 13' is energized from a suitable source of alternating current 15.

5 Operatively connected to the searchlight 10 'i mans non anenonuomerosirron.

pointed. Operatively' in such manner as to be responsive toits movement in azimuth is a second inductive device 16 similar in construction to the device 12. This second inductive device comprises a three-phase armature winding 17. and a winding 18 which is rotatably mount'- ed and has its shaft 18a operatively connected through suitablev gearing 19 to the searchlight 10 so as to be `moved in response to movement of they searchlight in azimuth.

The windings 13 and 18 are preferably connected tohe rotated in 1: 1 ratios with the telescope and searchlight respectively.

The inductive devices 12 and 16' are of the type citen used for transmitting an ular motion ln the present application, owever, the inductive devices are used for producing an alternating electromotive force which has a value dependent on the angular disagreement in azimuth or 'the 'telescope vand seerchlightA and which has a direction with respect to the alternating current sufi ply source 15 determined kby the direction of this disagreement. The devices are connected to the telescope and searchlight in such manner that when the searchlight is in angular agreement with the telescope, as' shown in the drawing, the winding 18 is in a position with relation to armature winding which is at right angles to the position 85 of the field winding 13 with relation to'` armature winding 14. ln this 'position ci winding 18, it is at right angles to the field generated by armature winding 17 due to energy supplied toit from inductive device 12. lt will be observed that iield windinr ifinduces a set oit voltages in 'the various, circuits of its cooperatingarmature winding 14, which set of voltages are impressed on armature windin 17 whereb a ield is set up by winding 1 having a, direction correspending to the direction of the field set up byA '.eld winding 13 so that it does not out winding .1 8 when in the position shown and hence no voltage is induced therein. In case 15 determined by the direction of the angular'disagreemen g The searchlight 10 is driven in azimuth by no lecce '15 tromotive force induced an electric nected in series driving motor of a direct current type which motor is controlled in response tothe voltage induced in winding 18 so Vas to maintainthe searchlight in angular agreement with the'telescope. The motor 20 is shown as provided with two armatures 21 and22 on a common driving shaft23, the armatures being provided with -eld windings 24 and 25. The field windings are conto a source ofdirect current supply 20a. ,As shown, shaft 23 is a continuation of shaft 18a and is connected through gearing 19 to the searchlight.

'For'the control of the motor 20 the elecin winding 18 upon angular disagreement of the telescope 'and the 'searchlight is impressed on the input or grid circuits of twojelectron discharge amplifyin devices or tubes 26 and 27, shown .20 as of t e three electrode type. This con- 35 impress an .alternating nection is preferably effected through. a transformer-2.8, the secondary 29 of which is provided with a central tap so that one half 30 of the secondary is connected inthe input or grid circuit of tube 26 while the other halt` 31 is connected in the input circuit o tube 27. The output or p-latecircuits of the tubes are-connected-to the two halves 32 and 33v of the primary of a trans-y former 34 having a secondary winding 35. The two tubes 26 and 27 are thus connected in a push pull or two wave circuit so as to reproduce both halves lof the electromotive force wave induced in winding 18 and thus voltage `on` transformer 34. The purpose of tubes 26 and 27 is to amplify the power output of the winding 18 so that only the very slight load re- `qulred to controlthe grids of the tubes is applied to the winding 18.

This amplified output of. winding 18 is impressed in turn on the .grid or input circuits of two electron discharge devices or tubes 36 and Y37 also shown of the` three ,45' electrode (type,

the entire voltage of the secondary of the Atransformer 34 being impressed on the grids of both tubes'. The plate: circuits of' the tubes 36 and 37 are energized from the alternating current supply source 15 through suitable transformers 38 and 39,v the connections of the transformers bein such that their voltages are' oppositein irection so that at anygiven instantthe plates of the tubes 3 6 and 37 have opposite polarities.. The arma-ture 21 transformer 34. Foregiample,

is connected in the plate circuit of tube 36 while the armature 22 is connected in the plate circuit of tube 37. .v l

As thus connected, it will be observed that 60 -'when transformer 34 impresses a voltage on and 37 due to moveone or the .other of will be*v energized dethe outputof if the. polarthe grids ofrtubes`36 ment of the telescope, the armatures 21 or 22 l pending on the polarity of ity of transformer 34 is` such that the grid of tube 36 is positive at the same instant that its plate ispositive, then a current will flow ,through armature 21, causing motor `20 to n operate in one direction, whereby the searchdirection, transformer 34 will impress a '-voltage having the opposite direction, that is, displaced 180 degrees in phase, on tubes 36 and 37 whereby the grid of' tube 37 will be positive 'atthe same instant that its plate is positive,lso"that a current will be caused to flow in armature 22 and the'motor 20 operated inthe opposite direction until the searchlight is again brought into angular agreement with the telescope. To improve the operation, and ,41 are connected across the two n,halves 30 and 31 of transformer secondary winding 29.

Inductance coils 42 and 43 are connected in series with the armatures 21and 22 respectively for the purpose of'increasing the inductance of the armature circuits. This increased inductance of the armature circuits tends to flatten out the pulsating currents supplied` thereto from the electron tubes," thereby improving'l the operation o the motor. .AA con across armature 21 and coil Y 42, while a condenser 45 is similarly connected across armature 22and coil 43.- The function of these condensers is to'absorb voltage surges due to the inductance of the armature circuits.

In the, modified form 'of our invention shown in Fig. 2, the armaturesare connected in series across the supply source, while the field coils l24 andA 25 are energizedvv fromthe vacuum tubes. a single armature and differential field coils may be used. Condensers 46 and 47 are conjnected across the field coils respectively to absorb voltage surges due ductance of the field coils, thus preventing arcing" and smoothing out the current flow in the yfield circuits.

' As shown in Fig.

to the self- 1n-v 3, for the purpose yor y Vmovement of the telescope in the opposite condensers 4() f denser 44 is connected llO Obviouslg;7 a motor having further amplification, the electron tubes may be connected to' selectively energizedifferential field coils-48 and 49 of an electric'V lies amgenerator 50,` which -in turn sup the elecplified ower to the armature A51 o tric vdriving The field coil 53 of the motor is connected acrossl'a suitable supply source 54. O viously if further amplification is desired, a plurality of generators 50 may be used motor 52 for the searchlight.

object and a driven object, a

connected so that the armature of one energizes the field of the next.

`While We have described our invention as embodied in concrete form and as operatingy skilled in the art Without departing from' the spirit of our invention, the scope of:

Which is set forth in the annexed claims.

l/Vhat We claim as new and desire to secure by Lettersv Patent of the United States is l. Means for reproducing position comprising incombination with va controlling object and a` drivenobject, a driving motor for said driven object, means for producing an electromotive force upon positional disagreement of said objects corresponding in value and direction to the amount and direction oi" said positional disagreement, and power amplifying means responsive to said electromotive force for controlling' said motor -whereby said motor is caused to drive said driven object into positional agreement with said controlling object.

2. Means' ior reproducing` position com-l S prising in combination with a controlling object and a driven object, driving means :for said .driven object, means for producing an alternating electromotive force upon anguiar disagreement oi said objects having 5 al direction determined by the directiono such angular disagreement, and povver ampliiying means responsive to said electromotive Sorce arranged to selectively apply its anipliiied output' to e9 in accordance with the direction of said electromotive force, whereby said motor is caused to drive said driven object. into positional agreement With said controlling object. Y

3. Means Lfor reproducing position cornprising in combination with a controlling obect and a driven ob'ect a drivin@ motor for said driven object, means for producing an electromotive orce upon positional disagreement or" said objects corresponding in value and direction to the amount and direction of such positional disagreement, and means comprising electron discharge devices responsive to said electromotive force for controlling said motor to drive said driven object into positional agreement with said controlling object.

hl/leans for reproducing position com.

nprising in combination with a controlling driving motor or said driven object, means for producing an electrornotive force upon positional disagreementoi said objects corresponding in .value and direction to the amountand ldirection oi said positional disagreement, and

control said motor electron discharge devices controlled by said electromotive force and connected to control the e'nergization of said motor so as to cause said motor to drive the driven object into positional agreement with the controlling object.

5. Means for 'reproducin position comprising in combination Wit a controlling object and a driven object, .an electric driving motor ,for said driven object, inductive means for producing an electromotive force upon positional disagreement of said 4objects corresponding in value and direction to the amount and direction of said posil tional disagreement, and a plurality of electron discharge devices for amplifying the output of said inductive means and connected to control the energization of said motor so as to cause said motor to drive the driven object into positional agreement with the controlling object.

6. Means for reproducing'position comprising in combination with a controlling object and a driven object, driving means .for said driven object, tivo electron discharge amplifying devices for controlling said driving means, a source of alternating current supply connected to energize the plate output circuits of said devices in opposite directions, and means for impressing a voltage on the input circuits of said devices having a direction corresponding to tliepolarity ci one or the other of the plates of said dr- -vices depending on the direc-ion oi tlc an gular disagreement betr-veen said objects. `whereby energy is supplied by one or the other ci said devices to cause the driven object to be driven into angular agreement with the controlling object.

'i'.Y Means for reproducing position comprising in combination with a controlling object and a driven object, an electric driving motor for said driven obiect, inductive means for producing an eiec'tromotive torce upon positional dise reement of said objects corresponding' in va ue and vdirection to the amount and direction of said positionalV disagreement, a source of alternating current supply for said inductive means, a plu rality of electron discharge anipliilying de- Avices having their input circuits energized by said inductive means and their output circuits energized in opposite directions from said supply source and connected tovcontrol said motor,` whereby energy is supplied `from one or theother of said devices depending on the direction of the angular disagreement between said'objects to cause said motor to drive the driven. object into angular agreement with the controlling objecti '8. Means for reproducing position comprising in combination with a controlling object ,and a driven object, an electric driving motor vfor said driven object, an inductive device connected to said controlling obllGV ject having -a polycircuit armature winding and a cooperating eld'winding, a source of alternating l current` supply for saidV field winding, an inductive devicehaving similar windings operatively "connected to said driven object, electrical connections between the armature windings of vsaid devices whereby an electromagnetic field is produced'by vthe armature winding offsaid second .device having a definite angular'.relationto the angular position of said controlling object .and inducing an electromotive force in the field `winding lof said second device corre-'f' spending in value, and directionv to the amount and direction `ofthe angular dis- .A agreement b'etween'saidv objects, and-a plurality of electron discharge devices having theirl input v'circuits vcontrolled response to said'electromotive force and their output circuits connected toy control said motor, and .electrical connections between the output cir- -cuits of said devices and said alternating i current supply 'source such that voltages of opposite dlrection are impressed on said out` But circuits, whereby said motor is controlled y one device to drive said driven object in ducing-'an electromotive force upon position-j.

al disagreement of said objects correspond'- ing in-value and direction -to the amount and direction of such positional disagreef ment, a p lurality of electron discharge deviceshavlng their input circuits energized. fbyA said electromotive force, a driving motor for said driven object, an 'electric generator for supplying energy toy said motor, a pluand electrical connections between said fields andthe output circuits of said electron discharge devices.

10. Means for reproducing position comprising in combination wit A object anda driven object, inductive means a controlling;

for producing an electromotive force upon positional disagreement of said objects cor- 'responding in .value .and direction to the amount and direction of such positionaldi'sagreement, a source of alternating current 'supply for said inductivemeans, two electron discharge devices havin theirinput circuits energized by said in uctive means Vand their output c1rcu1ts energized 1n opposite directions from said supply source, a,

driving motor for said controlled object, an electric generator-for supplying 'energy to said motor, a plurality of field windings for said generator, and electrical .connections between said field windings and the output circuits of said electron discharge devices.

In witness-whereof, we have hereunto set our hands this 1st day of August, 1923.

EDWARD M; HEWLETT.

WALDO W. WILLARD.

4s l rality of` iield windings'for said generator,A 

